AirSpaceMag.com

"We Called It 'The Bug'"

The Apollo Lunar Module wasn't pretty. But it got the job done.

The commander of the Challenger was in the zone, which was remarkable, considering his predicament. After all, he was piloting from a standing position. He was only 44 inches away from his crewmate but forced to speak to him through an intercom. And finally, he was peering through a bubble of Lexan, a pane of Chemcor structural glass, a sheet of Vycor meteorite-stopping glass, and around a hundred layers of infrared, thermal, and anti-fog coatings at a vista no other human had ever seen.

There, through Apollo 17 commander Gene Cernan’s small triangular window, the virginal, rolling, cratered Valley of Taurus-Littrow was unfolding before his eyes. But for Cernan and lunar module pilot Harrison Schmitt, the mountains, craters, and massifs were more than a remarkable panorama; they were signposts pointing the way to a landing zone that NASA scientists had selected on the southeastern shore of the moon’s Sea of Serenity.

Two hundred and fifty thousand miles away from the evolving final mission of Project Apollo, the men and women of Grumman Aerospace listened intently as the two astronauts put the lunar module through its paces. To them, the crew sounded like a well-oiled machine, and perhaps more importantly, the machine the crew was flying was matching the astronauts beat for beat. The Apollo lunar module was a Grumman design, and Apollo 17 was to be the company’s extraterrestrial swan song. But while the landing of 17 would be a crowning achievement for all “Grummies,” as NASA employees sometimes referred to them, for two smaller groups of Grumman employees it was the opportunity to settle a bet.

“The question was: Would anybody ever let the autopilot actually land the vehicle?” says former Grumman test pilot Tom Gwynne. “The [Grumman] pilots had bet a case of champagne with the engineers that nobody would actually let the autopilot land the lunar module. The engineering perspective was: The digital autopilot can do the best job, so why wouldn’t you? And the pilot perspective was: You have got one shot at it; what are you going to tell your grandchildren—that you let the autopilot land you on the moon?”

With 300 feet to go, the Challenger’s digital autopilot was still engaged and the engineers appeared to be winning the bet. It was December 11, 1972, a decade, a month, and four days since a fledgling NASA had placed a wager of its own. NASA had bet that a Long Island-based company known mostly for building capable but stout and somewhat unsightly aircraft for the U.S. Navy could build humanity’s first true spacecraft. (Such vehicles as NASA’s Mercury space capsule and the Soviet Vostok also flew in the vacuum of space, but unlike the LM, they were designed to meet the aerodynamic requirements of flying through Earth’s atmosphere during reentry.) “We got the contract in November of 1962,” says Thomas J. Kelly, Grumman’s chief engineer on the lunar module. “We had never built a manned spacecraft before. Nobody was an expert in those days, and they asked us to build a vehicle to land a man on the moon.”

NASA asked for a Lunar Excursion Module. “Then they changed the name,” says Kelly. “Somebody at NASA decided ‘excursion’ made it sound too flaky, so they changed the name to just plain old ‘lunar module.’ It was the easiest modification we made during the entire program.”

Changes came fast and furious in the early days of the LM. The original Grumman design called for a 22,000-pound, two-stage vehicle: a descent stage with five fixed landing gear that would carry the astronauts to the moon and an ascent stage that would power them back into lunar orbit. As far as piloting, designers rationalized that flying to the moon should be as much like a helicopter ride as possible, so they strapped the astronauts into two 75-pound seats and had them looking for acceptable landing spots out four huge, helicopter-like bubble windows.

But even the most junior aeronautical engineer back in 1962 knew that windows cause thermal, structural, and weight problems. The windows would have to get smaller. Still, there was no getting around the requirement that astronauts had to see where they were going. Then some bright bulb at NASA or Grumman (nobody recalls exactly who) realized that just because pilots always flew sitting down in the atmosphere did not mean they had to fly that way outside of it. (The closer an astronaut’s face is to the window, the greater his field of view, and a standing astronaut can position his face much closer to a window than a seated astronaut can.) Studies showed the astronauts would not encounter more than one third of Earth’s gravity during the flight of the LM. The result was that the astronauts would now stand side by side at a distance of 16 inches from a pair of two-square-foot windows. The new configuration gave them a 20-times-greater field of view from one-tenth the window area.

By October 1964, after almost two years and a mountain of engineering drawings, Grumman had a good idea what its now-33,000-pound lunar lander would look like—like no flying machine anybody had ever seen before. “You have to remember that the LM was carried in the Saturn’s protective shroud and only operated in the vacuum of space,” says Kelly. “That allowed us to design it from the inside out because we had no concerns for aerodynamics at all, which resulted in the distinctive look for the LM.”